X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8ad349bb6ed4a0be06e34c92be0d98b92e078db4..bb59bff194111743b33cc36712410b5656329d3c:/bsd/kern/sysv_msg.c

diff --git a/bsd/kern/sysv_msg.c b/bsd/kern/sysv_msg.c
index 8dcd30685..daca44630 100644
--- a/bsd/kern/sysv_msg.c
+++ b/bsd/kern/sysv_msg.c
@@ -1,31 +1,29 @@
 /*
- * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * This file contains Original Code and/or Modifications of Original Code 
- * as defined in and that are subject to the Apple Public Source License 
- * Version 2.0 (the 'License'). You may not use this file except in 
- * compliance with the License.  The rights granted to you under the 
- * License may not be used to create, or enable the creation or 
- * redistribution of, unlawful or unlicensed copies of an Apple operating 
- * system, or to circumvent, violate, or enable the circumvention or 
- * violation of, any terms of an Apple operating system software license 
- * agreement.
- *
- * Please obtain a copy of the License at 
- * http://www.opensource.apple.com/apsl/ and read it before using this 
- * file.
- *
- * The Original Code and all software distributed under the License are 
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
- * Please see the License for the specific language governing rights and 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
  * limitations under the License.
- *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * Implementation of SVID messages
@@ -45,6 +43,12 @@
  *
  * This software is provided ``AS IS'' without any warranties of any kind.
  */
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections.  This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -55,7 +59,7 @@
 #include <sys/malloc.h>
 #include <mach/mach_types.h>
 
-#include <bsm/audit_kernel.h>
+#include <security/audit/audit.h>
 
 #include <sys/filedesc.h>
 #include <sys/file_internal.h>
@@ -63,11 +67,20 @@
 #include <sys/sysproto.h>
 #include <sys/ipcs.h>
 
-static void msginit(void *);
+#if SYSV_MSG
+
+static int msginit(void *);
 
 #define MSG_DEBUG
 #undef MSG_DEBUG_OK
 
+/* Uncomment this line to see MAC debugging output. */
+/* #define	MAC_DEBUG */
+#if CONFIG_MACF_DEBUG
+#define	MPRINTF(a)	printf(a)
+#else
+#define	MPRINTF(a)
+#endif
 static void msg_freehdr(struct msg *msghdr);
 
 typedef int     sy_call_t(struct proc *, void *, int *);
@@ -84,7 +97,7 @@ static struct msg	*free_msghdrs;	/* list of free msg headers */
 char			*msgpool;	/* MSGMAX byte long msg buffer pool */
 struct msgmap		*msgmaps;	/* MSGSEG msgmap structures */
 struct msg		*msghdrs;	/* MSGTQL msg headers */
-struct user_msqid_ds	*msqids;	/* MSGMNI user_msqid_ds struct's */
+struct msqid_kernel	*msqids;	/* MSGMNI msqid_kernel structs (wrapping user_msqid_ds structs) */
 
 static lck_grp_t       *sysv_msg_subsys_lck_grp;
 static lck_grp_attr_t  *sysv_msg_subsys_lck_grp_attr;
@@ -98,6 +111,12 @@ void sysv_msg_lock_init(void);
 
 
 #ifdef __APPLE_API_PRIVATE
+	int	msgmax,		/* max chars in a message */
+		msgmni,		/* max message queue identifiers */
+		msgmnb,		/* max chars in a queue */
+		msgtql,		/* max messages in system */
+		msgssz,		/* size of a message segment (see notes above) */
+		msgseg;		/* number of message segments */
 struct msginfo msginfo = {
 		MSGMAX,		/* = (MSGSSZ*MSGSEG) : max chars in a message */
 		MSGMNI,		/* = 40 : max message queue identifiers */
@@ -113,12 +132,10 @@ __private_extern__ void
 sysv_msg_lock_init( void )
 {
 	sysv_msg_subsys_lck_grp_attr = lck_grp_attr_alloc_init();
-	lck_grp_attr_setstat(sysv_msg_subsys_lck_grp_attr);
 
 	sysv_msg_subsys_lck_grp = lck_grp_alloc_init("sysv_msg_subsys_lock", sysv_msg_subsys_lck_grp_attr);
 
 	sysv_msg_subsys_lck_attr = lck_attr_alloc_init();
-	/* lck_attr_setdebug(sysv_msg_subsys_lck_attr); */
 	lck_mtx_init(&sysv_msg_subsys_mutex, sysv_msg_subsys_lck_grp, sysv_msg_subsys_lck_attr);
 }
 
@@ -134,7 +151,21 @@ sysv_msgtime(void)
  * NOTE: Source and target may *NOT* overlap! (target is smaller)
  */
 static void
-msqid_ds_64to32(struct user_msqid_ds *in, struct msqid_ds *out)
+msqid_ds_kerneltouser32(struct user_msqid_ds *in, struct user32_msqid_ds *out)
+{
+	out->msg_perm	= in->msg_perm;
+	out->msg_qnum	= in->msg_qnum;
+	out->msg_cbytes	= in->msg_cbytes;	/* for ipcs */
+	out->msg_qbytes	= in->msg_qbytes;
+	out->msg_lspid	= in->msg_lspid;
+	out->msg_lrpid	= in->msg_lrpid;
+	out->msg_stime	= in->msg_stime;	/* XXX loss of range */
+	out->msg_rtime	= in->msg_rtime;	/* XXX loss of range */
+	out->msg_ctime	= in->msg_ctime;	/* XXX loss of range */
+}
+
+static void
+msqid_ds_kerneltouser64(struct user_msqid_ds *in, struct user64_msqid_ds *out)
 {
 	out->msg_perm	= in->msg_perm;
 	out->msg_qnum	= in->msg_qnum;
@@ -153,7 +184,21 @@ msqid_ds_64to32(struct user_msqid_ds *in, struct msqid_ds *out)
  * the beginning.
  */
 static void
-msqid_ds_32to64(struct msqid_ds *in, struct user_msqid_ds *out)
+msqid_ds_user32tokernel(struct user32_msqid_ds *in, struct user_msqid_ds *out)
+{
+	out->msg_ctime	= in->msg_ctime;
+	out->msg_rtime	= in->msg_rtime;
+	out->msg_stime	= in->msg_stime;
+	out->msg_lrpid	= in->msg_lrpid;
+	out->msg_lspid	= in->msg_lspid;
+	out->msg_qbytes	= in->msg_qbytes;
+	out->msg_cbytes	= in->msg_cbytes;	/* for ipcs */
+	out->msg_qnum	= in->msg_qnum;
+	out->msg_perm	= in->msg_perm;
+}
+
+static void
+msqid_ds_user64tokernel(struct user64_msqid_ds *in, struct user_msqid_ds *out)
 {
 	out->msg_ctime	= in->msg_ctime;
 	out->msg_rtime	= in->msg_rtime;
@@ -167,7 +212,7 @@ msqid_ds_32to64(struct msqid_ds *in, struct user_msqid_ds *out)
 }
 
 /* This routine assumes the system is locked prior to calling this routine */
-void 
+static int
 msginit(__unused void *dummy)
 {
 	static int initted = 0;
@@ -175,43 +220,63 @@ msginit(__unused void *dummy)
 
 	/* Lazy initialization on first system call; we don't have SYSINIT(). */
 	if (initted)
-		return;
-	initted = 1;
-
-	msgpool = (char *)_MALLOC(msginfo.msgmax, M_SHM, M_WAITOK);
-	MALLOC(msgmaps, struct msgmap *,
-			sizeof(struct msgmap) * msginfo.msgseg, 
-			M_SHM, M_WAITOK);
-	MALLOC(msghdrs, struct msg *,
-			sizeof(struct msg) * msginfo.msgtql, 
-			M_SHM, M_WAITOK);
-	MALLOC(msqids, struct user_msqid_ds *,
-			sizeof(struct user_msqid_ds) * msginfo.msgmni, 
-			M_SHM, M_WAITOK);
+		return (initted);
 
 	/*
 	 * msginfo.msgssz should be a power of two for efficiency reasons.
 	 * It is also pretty silly if msginfo.msgssz is less than 8
 	 * or greater than about 256 so ...
 	 */
-
 	i = 8;
 	while (i < 1024 && i != msginfo.msgssz)
 		i <<= 1;
     	if (i != msginfo.msgssz) {
-		printf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
-		    msginfo.msgssz);
-		panic("msginfo.msgssz not a small power of 2");
+		printf("msginfo.msgssz=%d (0x%x) not a small power of 2; resetting to %d\n", msginfo.msgssz, msginfo.msgssz, MSGSSZ);
+		msginfo.msgssz = MSGSSZ;
 	}
 
 	if (msginfo.msgseg > 32767) {
-		printf("msginfo.msgseg=%d\n", msginfo.msgseg);
-		panic("msginfo.msgseg > 32767");
+		printf("msginfo.msgseg=%d (> 32767); resetting to %d\n", msginfo.msgseg, MSGSEG);
+		msginfo.msgseg = MSGSEG;
+	}
+
+
+	/*
+	 * Allocate memory for message pool, maps, headers, and queue IDs;
+	 * if this fails, fail safely and leave it uninitialized (related
+	 * system calls will fail).
+	 */
+	msgpool = (char *)_MALLOC(msginfo.msgmax, M_SHM, M_WAITOK);
+	if (msgpool == NULL) {
+		printf("msginit: can't allocate msgpool");
+		goto bad;
+	}
+	MALLOC(msgmaps, struct msgmap *,
+			sizeof(struct msgmap) * msginfo.msgseg, 
+			M_SHM, M_WAITOK);
+	if (msgmaps == NULL) {
+		printf("msginit: can't allocate msgmaps");
+		goto bad;
 	}
 
-	if (msgmaps == NULL)
-		panic("msgmaps is NULL");
+	MALLOC(msghdrs, struct msg *,
+			sizeof(struct msg) * msginfo.msgtql, 
+			M_SHM, M_WAITOK);
+	if (msghdrs == NULL) {
+		printf("msginit: can't allocate msghdrs");
+		goto bad;
+	}
+
+	MALLOC(msqids, struct msqid_kernel *,
+			sizeof(struct user_msqid_ds) * msginfo.msgmni, 
+			M_SHM, M_WAITOK);
+	if (msqids == NULL) {
+		printf("msginit: can't allocate msqids");
+		goto bad;
+	}
 
+
+	/* init msgmaps */
 	for (i = 0; i < msginfo.msgseg; i++) {
 		if (i > 0)
 			msgmaps[i-1].next = i;
@@ -220,32 +285,68 @@ msginit(__unused void *dummy)
 	free_msgmaps = 0;
 	nfree_msgmaps = msginfo.msgseg;
 
-	if (msghdrs == NULL)
-		panic("msghdrs is NULL");
 
+	/* init msghdrs */
 	for (i = 0; i < msginfo.msgtql; i++) {
 		msghdrs[i].msg_type = 0;
 		if (i > 0)
 			msghdrs[i-1].msg_next = &msghdrs[i];
 		msghdrs[i].msg_next = NULL;
+#if CONFIG_MACF
+		mac_sysvmsg_label_init(&msghdrs[i]);
+#endif
     	}
 	free_msghdrs = &msghdrs[0];
 
-	if (msqids == NULL)
-		panic("msqids is NULL");
-
+	/* init msqids */
 	for (i = 0; i < msginfo.msgmni; i++) {
-		msqids[i].msg_qbytes = 0;	/* implies entry is available */
-		msqids[i].msg_perm.seq = 0;	/* reset to a known value */
+		msqids[i].u.msg_qbytes = 0;	/* implies entry is available */
+		msqids[i].u.msg_perm._seq = 0;	/* reset to a known value */
+		msqids[i].u.msg_perm.mode = 0;
+#if CONFIG_MACF
+		mac_sysvmsq_label_init(&msqids[i]);
+#endif
+	}
+
+	initted = 1;
+bad:
+	if (!initted) {
+		if (msgpool != NULL)
+			_FREE(msgpool, M_SHM);
+		if (msgmaps != NULL)
+			FREE(msgmaps, M_SHM);
+		if (msghdrs != NULL)
+			FREE(msghdrs, M_SHM);
+		if (msqids != NULL)
+			FREE(msqids, M_SHM);
 	}
+	return (initted);
 }
 
 /*
- * Entry point for all MSG calls
+ * msgsys
+ *
+ * Entry point for all MSG calls: msgctl, msgget, msgsnd, msgrcv
+ *
+ * Parameters:	p	Process requesting the call
+ * 		uap	User argument descriptor (see below)
+ * 		retval	Return value of the selected msg call
+ *
+ * Indirect parameters:	uap->which	msg call to invoke (index in array of msg calls)
+ * 			uap->a2		User argument descriptor
+ *                  
+ * Returns:	0	Success
+ * 		!0	Not success
+ *
+ * Implicit returns: retval	Return value of the selected msg call
+ *
+ * DEPRECATED:  This interface should not be used to call the other MSG
+ * 		functions (msgctl, msgget, msgsnd, msgrcv). The correct
+ * 		usage is to call the other MSG functions directly.
+ *
  */
-	/* XXX actually varargs. */
 int
-msgsys(struct proc *p, struct msgsys_args *uap, register_t *retval)
+msgsys(struct proc *p, struct msgsys_args *uap, int32_t *retval)
 {
 	if (uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
 		return (EINVAL);
@@ -273,22 +374,32 @@ msg_freehdr(struct msg *msghdr)
 		panic("msghdr->msg_spot != -1");
 	msghdr->msg_next = free_msghdrs;
 	free_msghdrs = msghdr;
+#if CONFIG_MACF
+	mac_sysvmsg_label_recycle(msghdr);
+#endif
+	/*
+	 * Notify waiters that there are free message headers and segments
+	 * now available.
+	 */
+	wakeup((caddr_t)&free_msghdrs);
 }
 
 int
-msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
+msgctl(struct proc *p, struct msgctl_args *uap, int32_t *retval)
 {
 	int msqid = uap->msqid;
 	int cmd = uap->cmd;
 	kauth_cred_t cred = kauth_cred_get();
 	int rval, eval;
 	struct user_msqid_ds msqbuf;
-	struct user_msqid_ds *msqptr;
-	struct user_msqid_ds umsds;
+	struct msqid_kernel *msqptr;
 
 	SYSV_MSG_SUBSYS_LOCK();
 
-	msginit( 0);
+	if (!msginit(0)) {
+		eval =  ENOMEM;
+		goto msgctlout;
+	}
 
 #ifdef MSG_DEBUG_OK
 	printf("call to msgctl(%d, %d, 0x%qx)\n", msqid, cmd, uap->buf);
@@ -309,20 +420,25 @@ msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
 
 	msqptr = &msqids[msqid];
 
-	if (msqptr->msg_qbytes == 0) {
+	if (msqptr->u.msg_qbytes == 0) {
 #ifdef MSG_DEBUG_OK
 		printf("no such msqid\n");
 #endif
 		eval = EINVAL;
 		goto msgctlout;
 	}
-	if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
+	if (msqptr->u.msg_perm._seq != IPCID_TO_SEQ(uap->msqid)) {
 #ifdef MSG_DEBUG_OK
 		printf("wrong sequence number\n");
 #endif
 		eval = EINVAL;
 		goto msgctlout;
 	}
+#if CONFIG_MACF
+	eval = mac_sysvmsq_check_msqctl(kauth_cred_get(), msqptr, cmd);
+	if (eval) 
+		goto msgctlout;
+#endif
 
 	eval = 0;
 	rval = 0;
@@ -332,28 +448,47 @@ msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
 	case IPC_RMID:
 	{
 		struct msg *msghdr;
-		if ((eval = ipcperm(cred, &msqptr->msg_perm, IPC_M)))
+		if ((eval = ipcperm(cred, &msqptr->u.msg_perm, IPC_M)))
 			goto msgctlout;
-
+#if CONFIG_MACF
+		/*
+		 * Check that the thread has MAC access permissions to
+		 * individual msghdrs.  Note: We need to do this in a
+		 * separate loop because the actual loop alters the
+		 * msq/msghdr info as it progresses, and there is no going
+		 * back if half the way through we discover that the
+		 * thread cannot free a certain msghdr.  The msq will get
+		 * into an inconsistent state.
+		 */
+		for (msghdr = msqptr->u.msg_first; msghdr != NULL;
+		    msghdr = msghdr->msg_next) {
+			eval = mac_sysvmsq_check_msgrmid(kauth_cred_get(), msghdr);
+			if (eval) 
+				goto msgctlout;
+		}
+#endif
 		/* Free the message headers */
-		msghdr = msqptr->msg_first;
+		msghdr = msqptr->u.msg_first;
 		while (msghdr != NULL) {
 			struct msg *msghdr_tmp;
 
 			/* Free the segments of each message */
-			msqptr->msg_cbytes -= msghdr->msg_ts;
-			msqptr->msg_qnum--;
+			msqptr->u.msg_cbytes -= msghdr->msg_ts;
+			msqptr->u.msg_qnum--;
 			msghdr_tmp = msghdr;
 			msghdr = msghdr->msg_next;
 			msg_freehdr(msghdr_tmp);
 		}
 
-		if (msqptr->msg_cbytes != 0)
+		if (msqptr->u.msg_cbytes != 0)
 			panic("msg_cbytes is messed up");
-		if (msqptr->msg_qnum != 0)
+		if (msqptr->u.msg_qnum != 0)
 			panic("msg_qnum is messed up");
 
-		msqptr->msg_qbytes = 0;	/* Mark it as free */
+		msqptr->u.msg_qbytes = 0;	/* Mark it as free */
+#if CONFIG_MACF
+		mac_sysvmsq_label_recycle(msqptr);
+#endif
 
 		wakeup((caddr_t)msqptr);
 	}
@@ -361,24 +496,29 @@ msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
 		break;
 
 	case IPC_SET:
-		if ((eval = ipcperm(cred, &msqptr->msg_perm, IPC_M)))
+		if ((eval = ipcperm(cred, &msqptr->u.msg_perm, IPC_M)))
 			goto msgctlout;
 
 		SYSV_MSG_SUBSYS_UNLOCK();
 
 		if (IS_64BIT_PROCESS(p)) {
-			eval = copyin(uap->buf, &msqbuf, sizeof(struct user_msqid_ds));
+			struct user64_msqid_ds tmpds;
+			eval = copyin(uap->buf, &tmpds, sizeof(tmpds));
+
+			msqid_ds_user64tokernel(&tmpds, &msqbuf);
 		} else {
-			eval = copyin(uap->buf, &msqbuf, sizeof(struct msqid_ds));
-			/* convert in place; ugly, but safe */
-			msqid_ds_32to64((struct msqid_ds *)&msqbuf, &msqbuf);
+			struct user32_msqid_ds tmpds;
+
+			eval = copyin(uap->buf, &tmpds, sizeof(tmpds));
+
+			msqid_ds_user32tokernel(&tmpds, &msqbuf);
 		}
 		if (eval)
 			return(eval);
 
 		SYSV_MSG_SUBSYS_LOCK();
 
-		if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
+		if (msqbuf.msg_qbytes > msqptr->u.msg_qbytes) {
 			eval = suser(cred, &p->p_acflag);
 			if (eval)
 				goto msgctlout;
@@ -386,7 +526,7 @@ msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
 
 
 		/* compare (msglen_t) value against restrict (int) value */
-		if (msqbuf.msg_qbytes > (msglen_t)msginfo.msgmnb) {
+		if (msqbuf.msg_qbytes > (user_msglen_t)msginfo.msgmnb) {
 #ifdef MSG_DEBUG_OK
 			printf("can't increase msg_qbytes beyond %d (truncating)\n",
 			    msginfo.msgmnb);
@@ -400,31 +540,31 @@ msgctl(struct proc *p, struct msgctl_args *uap, register_t *retval)
 			eval = EINVAL;
 			goto msgctlout;
 		}
-		msqptr->msg_perm.uid = msqbuf.msg_perm.uid;	/* change the owner */
-		msqptr->msg_perm.gid = msqbuf.msg_perm.gid;	/* change the owner */
-		msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
+		msqptr->u.msg_perm.uid = msqbuf.msg_perm.uid;	/* change the owner */
+		msqptr->u.msg_perm.gid = msqbuf.msg_perm.gid;	/* change the owner */
+		msqptr->u.msg_perm.mode = (msqptr->u.msg_perm.mode & ~0777) |
 		    (msqbuf.msg_perm.mode & 0777);
-		msqptr->msg_qbytes = msqbuf.msg_qbytes;
-		msqptr->msg_ctime = sysv_msgtime();
+		msqptr->u.msg_qbytes = msqbuf.msg_qbytes;
+		msqptr->u.msg_ctime = sysv_msgtime();
 		break;
 
 	case IPC_STAT:
-		if ((eval = ipcperm(cred, &msqptr->msg_perm, IPC_R))) {
+		if ((eval = ipcperm(cred, &msqptr->u.msg_perm, IPC_R))) {
 #ifdef MSG_DEBUG_OK
 			printf("requester doesn't have read access\n");
 #endif
 			goto msgctlout;
 		}
 
-		bcopy(msqptr, &umsds, sizeof(struct user_msqid_ds));
-
 		SYSV_MSG_SUBSYS_UNLOCK();
 		if (IS_64BIT_PROCESS(p)) {
-			eval = copyout(&umsds, uap->buf, sizeof(struct user_msqid_ds));
+			struct user64_msqid_ds msqid_ds64;
+			msqid_ds_kerneltouser64(&msqptr->u, &msqid_ds64);
+			eval = copyout(&msqid_ds64, uap->buf, sizeof(msqid_ds64));
 		} else {
-			struct msqid_ds msqid_ds32;
-			msqid_ds_64to32(&umsds, &msqid_ds32);
-			eval = copyout(&msqid_ds32, uap->buf, sizeof(struct msqid_ds));
+			struct user32_msqid_ds msqid_ds32;
+			msqid_ds_kerneltouser32(&msqptr->u, &msqid_ds32);
+			eval = copyout(&msqid_ds32, uap->buf, sizeof(msqid_ds32));
 		}
 		SYSV_MSG_SUBSYS_LOCK();
 		break;
@@ -445,16 +585,20 @@ msgctlout:
 }
 
 int
-msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
+msgget(__unused struct proc *p, struct msgget_args *uap, int32_t *retval)
 {
 	int msqid, eval;
 	int key = uap->key;
 	int msgflg = uap->msgflg;
 	kauth_cred_t cred = kauth_cred_get();
-	struct user_msqid_ds *msqptr = NULL;
+	struct msqid_kernel *msqptr = NULL;
 
 	SYSV_MSG_SUBSYS_LOCK();
-	msginit( 0);
+
+	if (!msginit(0)) {
+		eval =  ENOMEM;
+		goto msggetout;
+	}
 
 #ifdef MSG_DEBUG_OK
 	printf("msgget(0x%x, 0%o)\n", key, msgflg);
@@ -463,8 +607,8 @@ msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
 	if (key != IPC_PRIVATE) {
 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
 			msqptr = &msqids[msqid];
-			if (msqptr->msg_qbytes != 0 &&
-			    msqptr->msg_perm.key == key)
+			if (msqptr->u.msg_qbytes != 0 &&
+			    msqptr->u.msg_perm._key == key)
 				break;
 		}
 		if (msqid < msginfo.msgmni) {
@@ -478,13 +622,18 @@ msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
 				eval = EEXIST;
 				goto msggetout;
 			}
-			if ((eval = ipcperm(cred, &msqptr->msg_perm, msgflg & 0700 ))) {
+			if ((eval = ipcperm(cred, &msqptr->u.msg_perm, msgflg & 0700 ))) {
 #ifdef MSG_DEBUG_OK
 				printf("requester doesn't have 0%o access\n",
 				    msgflg & 0700);
 #endif
 				goto msggetout;
 			}
+#if CONFIG_MACF
+			eval = mac_sysvmsq_check_msqget(cred, msqptr);
+			if (eval) 
+				goto msggetout;
+#endif
 			goto found;
 		}
 	}
@@ -501,8 +650,8 @@ msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
 			 * can't re-use the entry until they release it.
 			 */
 			msqptr = &msqids[msqid];
-			if (msqptr->msg_qbytes == 0 &&
-			    (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
+			if (msqptr->u.msg_qbytes == 0 &&
+			    (msqptr->u.msg_perm.mode & MSG_LOCKED) == 0)
 				break;
 		}
 		if (msqid == msginfo.msgmni) {
@@ -515,24 +664,27 @@ msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
 #ifdef MSG_DEBUG_OK
 		printf("msqid %d is available\n", msqid);
 #endif
-		msqptr->msg_perm.key = key;
-		msqptr->msg_perm.cuid = kauth_cred_getuid(cred);
-		msqptr->msg_perm.uid = kauth_cred_getuid(cred);
-		msqptr->msg_perm.cgid = cred->cr_gid;
-		msqptr->msg_perm.gid = cred->cr_gid;
-		msqptr->msg_perm.mode = (msgflg & 0777);
+		msqptr->u.msg_perm._key = key;
+		msqptr->u.msg_perm.cuid = kauth_cred_getuid(cred);
+		msqptr->u.msg_perm.uid = kauth_cred_getuid(cred);
+		msqptr->u.msg_perm.cgid = kauth_cred_getgid(cred);
+		msqptr->u.msg_perm.gid = kauth_cred_getgid(cred);
+		msqptr->u.msg_perm.mode = (msgflg & 0777);
 		/* Make sure that the returned msqid is unique */
-		msqptr->msg_perm.seq++;
-		msqptr->msg_first = NULL;
-		msqptr->msg_last = NULL;
-		msqptr->msg_cbytes = 0;
-		msqptr->msg_qnum = 0;
-		msqptr->msg_qbytes = msginfo.msgmnb;
-		msqptr->msg_lspid = 0;
-		msqptr->msg_lrpid = 0;
-		msqptr->msg_stime = 0;
-		msqptr->msg_rtime = 0;
-		msqptr->msg_ctime = sysv_msgtime();
+		msqptr->u.msg_perm._seq++;
+		msqptr->u.msg_first = NULL;
+		msqptr->u.msg_last = NULL;
+		msqptr->u.msg_cbytes = 0;
+		msqptr->u.msg_qnum = 0;
+		msqptr->u.msg_qbytes = msginfo.msgmnb;
+		msqptr->u.msg_lspid = 0;
+		msqptr->u.msg_lrpid = 0;
+		msqptr->u.msg_stime = 0;
+		msqptr->u.msg_rtime = 0;
+		msqptr->u.msg_ctime = sysv_msgtime();
+#if CONFIG_MACF
+		mac_sysvmsq_label_associate(cred, msqptr);
+#endif
 	} else {
 #ifdef MSG_DEBUG_OK
 		printf("didn't find it and wasn't asked to create it\n");
@@ -543,7 +695,7 @@ msgget(__unused struct proc *p, struct msgget_args *uap, register_t *retval)
 
 found:
 	/* Construct the unique msqid */
-	*retval = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
+	*retval = IXSEQ_TO_IPCID(msqid, msqptr->u.msg_perm);
 	AUDIT_ARG(svipc_id, *retval);
 	eval = 0;
 msggetout:
@@ -553,24 +705,35 @@ msggetout:
 
 
 int
-msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
+msgsnd(struct proc *p, struct msgsnd_args *uap, int32_t *retval)
+{
+	__pthread_testcancel(1);
+	return(msgsnd_nocancel(p, (struct msgsnd_nocancel_args *)uap, retval));
+}
+
+int
+msgsnd_nocancel(struct proc *p, struct msgsnd_nocancel_args *uap, int32_t *retval)
 {
 	int msqid = uap->msqid;
 	user_addr_t user_msgp = uap->msgp;
 	size_t msgsz = (size_t)uap->msgsz;	/* limit to 4G */
 	int msgflg = uap->msgflg;
 	int segs_needed, eval;
-	struct user_msqid_ds *msqptr;
+	struct msqid_kernel *msqptr;
 	struct msg *msghdr;
 	short next;
 	user_long_t msgtype;
 
 
 	SYSV_MSG_SUBSYS_LOCK();
-	msginit( 0);
+
+	if (!msginit(0)) {
+		eval =  ENOMEM;
+		goto msgsndout;
+	}
 
 #ifdef MSG_DEBUG_OK
-	printf("call to msgsnd(%d, 0x%qx, %d, %d)\n", msqid, user_msgp, msgsz,
+	printf("call to msgsnd(%d, 0x%qx, %ld, %d)\n", msqid, user_msgp, msgsz,
 	    msgflg);
 #endif
 
@@ -587,14 +750,14 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 	}
 
 	msqptr = &msqids[msqid];
-	if (msqptr->msg_qbytes == 0) {
+	if (msqptr->u.msg_qbytes == 0) {
 #ifdef MSG_DEBUG_OK
 		printf("no such message queue id\n");
 #endif
 		eval = EINVAL;
 		goto msgsndout;
 	}
-	if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
+	if (msqptr->u.msg_perm._seq != IPCID_TO_SEQ(uap->msqid)) {
 #ifdef MSG_DEBUG_OK
 		printf("wrong sequence number\n");
 #endif
@@ -602,27 +765,39 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 		goto msgsndout;
 	}
 
-	if ((eval = ipcperm(kauth_cred_get(), &msqptr->msg_perm, IPC_W))) {
+	if ((eval = ipcperm(kauth_cred_get(), &msqptr->u.msg_perm, IPC_W))) {
 #ifdef MSG_DEBUG_OK
 		printf("requester doesn't have write access\n");
 #endif
 		goto msgsndout;
 	}
 
+#if CONFIG_MACF
+	eval = mac_sysvmsq_check_msqsnd(kauth_cred_get(), msqptr);
+	if (eval) 
+		goto msgsndout;
+#endif
 	segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
 #ifdef MSG_DEBUG_OK
-	printf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
+	printf("msgsz=%ld, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
 	    segs_needed);
 #endif
+
+	/*
+	 * If we suffer resource starvation, we will sleep in this loop and
+	 * wait for more resources to become available.  This is a loop to
+	 * ensure reacquisition of the mutex following any sleep, since there
+	 * are multiple resources under contention.
+	 */
 	for (;;) {
-		int need_more_resources = 0;
+		void *blocking_resource = NULL;
 
 		/*
-		 * check msgsz
-		 * (inside this loop in case msg_qbytes changes while we sleep)
+		 * Check that we have not had the maximum message size change
+		 * out from under us and render our message invalid while we
+		 * slept waiting for some resource.
 		 */
-
-		if (msgsz > msqptr->msg_qbytes) {
+		if (msgsz > msqptr->u.msg_qbytes) {
 #ifdef MSG_DEBUG_OK
 			printf("msgsz > msqptr->msg_qbytes\n");
 #endif
@@ -630,32 +805,49 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 			goto msgsndout;
 		}
 
-		if (msqptr->msg_perm.mode & MSG_LOCKED) {
+		/*
+		 * If the user_msqid_ds is already locked, we need to sleep on
+		 * the queue until it's unlocked.
+		 */
+		if (msqptr->u.msg_perm.mode & MSG_LOCKED) {
 #ifdef MSG_DEBUG_OK
 			printf("msqid is locked\n");
 #endif
-			need_more_resources = 1;
+			blocking_resource = msqptr;
 		}
-		if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
+
+		/*
+		 * If our message plus the messages already in the queue would
+		 * cause us to exceed the maximum number of bytes wer are
+		 * permitted to queue, then block on the queue until it drains.
+		 */
+		if (msgsz + msqptr->u.msg_cbytes > msqptr->u.msg_qbytes) {
 #ifdef MSG_DEBUG_OK
 			printf("msgsz + msg_cbytes > msg_qbytes\n");
 #endif
-			need_more_resources = 1;
+			blocking_resource = msqptr;
 		}
+
+		/*
+		 * Both message maps and message headers are protected by
+		 * sleeping on the address of the pointer to the list of free
+		 * message headers, since they are allocated and freed in
+		 * tandem.
+		 */
 		if (segs_needed > nfree_msgmaps) {
 #ifdef MSG_DEBUG_OK
 			printf("segs_needed > nfree_msgmaps\n");
 #endif
-			need_more_resources = 1;
+			blocking_resource = &free_msghdrs;
 		}
 		if (free_msghdrs == NULL) {
 #ifdef MSG_DEBUG_OK
 			printf("no more msghdrs\n");
 #endif
-			need_more_resources = 1;
+			blocking_resource = &free_msghdrs;
 		}
 
-		if (need_more_resources) {
+		if (blocking_resource != NULL) {
 			int we_own_it;
 
 			if ((msgflg & IPC_NOWAIT) != 0) {
@@ -666,7 +858,7 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 				goto msgsndout;
 			}
 
-			if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
+			if ((msqptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
 #ifdef MSG_DEBUG_OK
 				printf("we don't own the user_msqid_ds\n");
 #endif
@@ -677,19 +869,19 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 #ifdef MSG_DEBUG_OK
 				printf("we own the user_msqid_ds\n");
 #endif
-				msqptr->msg_perm.mode |= MSG_LOCKED;
+				msqptr->u.msg_perm.mode |= MSG_LOCKED;
 				we_own_it = 1;
 			}
 #ifdef MSG_DEBUG_OK
 			printf("goodnight\n");
 #endif
-			eval = msleep((caddr_t)msqptr, &sysv_msg_subsys_mutex, (PZERO - 4) | PCATCH,
+			eval = msleep(blocking_resource, &sysv_msg_subsys_mutex, (PZERO - 4) | PCATCH,
 			    "msgwait", 0);
 #ifdef MSG_DEBUG_OK
 			printf("good morning, eval=%d\n", eval);
 #endif
 			if (we_own_it)
-				msqptr->msg_perm.mode &= ~MSG_LOCKED;
+				msqptr->u.msg_perm.mode &= ~MSG_LOCKED;
 			if (eval != 0) {
 #ifdef MSG_DEBUG_OK
 				printf("msgsnd:  interrupted system call\n");
@@ -702,18 +894,11 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 			 * Make sure that the msq queue still exists
 			 */
 
-			if (msqptr->msg_qbytes == 0) {
+			if (msqptr->u.msg_qbytes == 0) {
 #ifdef MSG_DEBUG_OK
 				printf("msqid deleted\n");
 #endif
-				/* The SVID says to return EIDRM. */
-#ifdef EIDRM
 				eval = EIDRM;
-#else
-				/* Unfortunately, BSD doesn't define that code
-				   yet! */
-				eval = EINVAL;
-#endif
 				goto msgsndout;
 			
 			}
@@ -731,11 +916,11 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 	 * Make sure!
 	 */
 
-	if (msqptr->msg_perm.mode & MSG_LOCKED)
+	if (msqptr->u.msg_perm.mode & MSG_LOCKED)
 		panic("msg_perm.mode & MSG_LOCKED");
 	if (segs_needed > nfree_msgmaps)
 		panic("segs_needed > nfree_msgmaps");
-	if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
+	if (msgsz + msqptr->u.msg_cbytes > msqptr->u.msg_qbytes)
 		panic("msgsz + msg_cbytes > msg_qbytes");
 	if (free_msghdrs == NULL)
 		panic("no more msghdrs");
@@ -744,20 +929,21 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 	 * Re-lock the user_msqid_ds in case we page-fault when copying in
 	 * the message
 	 */
-
-	if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
+	if ((msqptr->u.msg_perm.mode & MSG_LOCKED) != 0)
 		panic("user_msqid_ds is already locked");
-	msqptr->msg_perm.mode |= MSG_LOCKED;
+	msqptr->u.msg_perm.mode |= MSG_LOCKED;
 
 	/*
 	 * Allocate a message header
 	 */
-
 	msghdr = free_msghdrs;
 	free_msghdrs = msghdr->msg_next;
 	msghdr->msg_spot = -1;
 	msghdr->msg_ts = msgsz;
 
+#if CONFIG_MACF
+	mac_sysvmsg_label_associate(kauth_cred_get(), msqptr, msghdr);
+#endif
 	/*
 	 * Allocate space for the message
 	 */
@@ -794,9 +980,11 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 		user_msgp = user_msgp + sizeof(msgtype);	/* ptr math */
 	} else {
 		SYSV_MSG_SUBSYS_UNLOCK();
-		eval = copyin(user_msgp, &msghdr->msg_type, sizeof(long));
+		int32_t msg_type32;
+		eval = copyin(user_msgp, &msg_type32, sizeof(msg_type32));
+		msghdr->msg_type = msg_type32;
 		SYSV_MSG_SUBSYS_LOCK();
-		user_msgp = user_msgp + sizeof(long);		/* ptr math */
+		user_msgp = user_msgp + sizeof(msg_type32);		/* ptr math */
 	}
 
 	if (eval != 0) {
@@ -804,7 +992,7 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 		printf("error %d copying the message type\n", eval);
 #endif
 		msg_freehdr(msghdr);
-		msqptr->msg_perm.mode &= ~MSG_LOCKED;
+		msqptr->u.msg_perm.mode &= ~MSG_LOCKED;
 		wakeup((caddr_t)msqptr);
 		goto msgsndout;
 	}
@@ -815,10 +1003,10 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 	 */
 	if (msghdr->msg_type < 1) {
 		msg_freehdr(msghdr);
-		msqptr->msg_perm.mode &= ~MSG_LOCKED;
+		msqptr->u.msg_perm.mode &= ~MSG_LOCKED;
 		wakeup((caddr_t)msqptr);
 #ifdef MSG_DEBUG_OK
-		printf("mtype (%d) < 1\n", msghdr->msg_type);
+		printf("mtype (%ld) < 1\n", msghdr->msg_type);
 #endif
 		eval = EINVAL;
 		goto msgsndout;
@@ -849,7 +1037,7 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 			printf("error %d copying in message segment\n", eval);
 #endif
 			msg_freehdr(msghdr);
-			msqptr->msg_perm.mode &= ~MSG_LOCKED;
+			msqptr->u.msg_perm.mode &= ~MSG_LOCKED;
 			wakeup((caddr_t)msqptr);
 
 			goto msgsndout;
@@ -865,13 +1053,13 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 	 * We've got the message.  Unlock the user_msqid_ds.
 	 */
 
-	msqptr->msg_perm.mode &= ~MSG_LOCKED;
+	msqptr->u.msg_perm.mode &= ~MSG_LOCKED;
 
 	/*
 	 * Make sure that the user_msqid_ds is still allocated.
 	 */
 
-	if (msqptr->msg_qbytes == 0) {
+	if (msqptr->u.msg_qbytes == 0) {
 		msg_freehdr(msghdr);
 		wakeup((caddr_t)msqptr);
 		/* The SVID says to return EIDRM. */
@@ -884,23 +1072,42 @@ msgsnd(struct proc *p, struct msgsnd_args *uap, register_t *retval)
 		goto msgsndout;
 	}
 
+#if CONFIG_MACF
+	/*
+	 * Note: Since the task/thread allocates the msghdr and usually
+	 * primes it with its own MAC label, for a majority of policies, it
+	 * won't be necessary to check whether the msghdr has access
+	 * permissions to the msgq.  The mac_sysvmsq_check_msqsnd check would
+	 * suffice in that case.  However, this hook may be required where
+	 * individual policies derive a non-identical label for the msghdr
+	 * from the current thread label and may want to check the msghdr
+	 * enqueue permissions, along with read/write permissions to the
+	 * msgq.
+	 */
+	eval = mac_sysvmsq_check_enqueue(kauth_cred_get(), msghdr, msqptr);
+	if (eval) {
+		msg_freehdr(msghdr);
+		wakeup((caddr_t) msqptr);
+		goto msgsndout;
+	}
+#endif
 	/*
 	 * Put the message into the queue
 	 */
 
-	if (msqptr->msg_first == NULL) {
-		msqptr->msg_first = msghdr;
-		msqptr->msg_last = msghdr;
+	if (msqptr->u.msg_first == NULL) {
+		msqptr->u.msg_first = msghdr;
+		msqptr->u.msg_last = msghdr;
 	} else {
-		msqptr->msg_last->msg_next = msghdr;
-		msqptr->msg_last = msghdr;
+		msqptr->u.msg_last->msg_next = msghdr;
+		msqptr->u.msg_last = msghdr;
 	}
-	msqptr->msg_last->msg_next = NULL;
+	msqptr->u.msg_last->msg_next = NULL;
 
-	msqptr->msg_cbytes += msghdr->msg_ts;
-	msqptr->msg_qnum++;
-	msqptr->msg_lspid = p->p_pid;
-	msqptr->msg_stime = sysv_msgtime();
+	msqptr->u.msg_cbytes += msghdr->msg_ts;
+	msqptr->u.msg_qnum++;
+	msqptr->u.msg_lspid = p->p_pid;
+	msqptr->u.msg_stime = sysv_msgtime();
 
 	wakeup((caddr_t)msqptr);
 	*retval = 0;
@@ -914,6 +1121,13 @@ msgsndout:
 
 int
 msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
+{
+	__pthread_testcancel(1);
+	return(msgrcv_nocancel(p, (struct msgrcv_nocancel_args *)uap, retval));
+}
+
+int
+msgrcv_nocancel(struct proc *p, struct msgrcv_nocancel_args *uap, user_ssize_t *retval)
 {
 	int msqid = uap->msqid;
 	user_addr_t user_msgp = uap->msgp;
@@ -921,18 +1135,22 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 	long msgtyp = (long)uap->msgtyp;	/* limit to 32 bits */
 	int msgflg = uap->msgflg;
 	size_t len;
-	struct user_msqid_ds *msqptr;
+	struct msqid_kernel *msqptr;
 	struct msg *msghdr;
 	int eval;
 	short next;
 	user_long_t msgtype;
-	long msg_type_long;
+	int32_t msg_type32;
 
 	SYSV_MSG_SUBSYS_LOCK();
-	msginit( 0);
+
+	if (!msginit(0)) {
+		eval =  ENOMEM;
+		goto msgrcvout;
+	}
 
 #ifdef MSG_DEBUG_OK
-	printf("call to msgrcv(%d, 0x%qx, %d, %ld, %d)\n", msqid, user_msgp,
+	printf("call to msgrcv(%d, 0x%qx, %ld, %ld, %d)\n", msqid, user_msgp,
 	    msgsz, msgtyp, msgflg);
 #endif
 
@@ -949,14 +1167,14 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 	}
 
 	msqptr = &msqids[msqid];
-	if (msqptr->msg_qbytes == 0) {
+	if (msqptr->u.msg_qbytes == 0) {
 #ifdef MSG_DEBUG_OK
 		printf("no such message queue id\n");
 #endif
 		eval = EINVAL;
 		goto msgrcvout;
 	}
-	if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
+	if (msqptr->u.msg_perm._seq != IPCID_TO_SEQ(uap->msqid)) {
 #ifdef MSG_DEBUG_OK
 		printf("wrong sequence number\n");
 #endif
@@ -964,33 +1182,44 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 		goto msgrcvout;
 	}
 
-	if ((eval = ipcperm(kauth_cred_get(), &msqptr->msg_perm, IPC_R))) {
+	if ((eval = ipcperm(kauth_cred_get(), &msqptr->u.msg_perm, IPC_R))) {
 #ifdef MSG_DEBUG_OK
 		printf("requester doesn't have read access\n");
 #endif
 		goto msgrcvout;
 	}
 
+#if CONFIG_MACF
+	eval = mac_sysvmsq_check_msqrcv(kauth_cred_get(), msqptr);
+	if (eval) 
+		goto msgrcvout;
+#endif
 	msghdr = NULL;
 	while (msghdr == NULL) {
 		if (msgtyp == 0) {
-			msghdr = msqptr->msg_first;
+			msghdr = msqptr->u.msg_first;
 			if (msghdr != NULL) {
 				if (msgsz < msghdr->msg_ts &&
 				    (msgflg & MSG_NOERROR) == 0) {
 #ifdef MSG_DEBUG_OK
-					printf("first message on the queue is too big (want %d, got %d)\n",
+					printf("first message on the queue is too big (want %ld, got %d)\n",
 					    msgsz, msghdr->msg_ts);
 #endif
 					eval = E2BIG;
 					goto msgrcvout;
 				}
-				if (msqptr->msg_first == msqptr->msg_last) {
-					msqptr->msg_first = NULL;
-					msqptr->msg_last = NULL;
+#if CONFIG_MACF
+				eval = mac_sysvmsq_check_msgrcv(kauth_cred_get(),
+				    msghdr);
+				if (eval) 
+					goto msgrcvout;
+#endif
+				if (msqptr->u.msg_first == msqptr->u.msg_last) {
+					msqptr->u.msg_first = NULL;
+					msqptr->u.msg_last = NULL;
 				} else {
-					msqptr->msg_first = msghdr->msg_next;
-					if (msqptr->msg_first == NULL)
+					msqptr->u.msg_first = msghdr->msg_next;
+					if (msqptr->u.msg_first == NULL)
 						panic("msg_first/last messed up #1");
 				}
 			}
@@ -999,7 +1228,7 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 			struct msg **prev;
 
 			previous = NULL;
-			prev = &(msqptr->msg_first);
+			prev = &(msqptr->u.msg_first);
 			while ((msghdr = *prev) != NULL) {
 				/*
 				 * Is this message's type an exact match or is
@@ -1013,33 +1242,39 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 				if (msgtyp == msghdr->msg_type ||
 				    msghdr->msg_type <= -msgtyp) {
 #ifdef MSG_DEBUG_OK
-					printf("found message type %d, requested %d\n",
+					printf("found message type %ld, requested %ld\n",
 					    msghdr->msg_type, msgtyp);
 #endif
 					if (msgsz < msghdr->msg_ts &&
 					    (msgflg & MSG_NOERROR) == 0) {
 #ifdef MSG_DEBUG_OK
-						printf("requested message on the queue is too big (want %d, got %d)\n",
+						printf("requested message on the queue is too big (want %ld, got %d)\n",
 						    msgsz, msghdr->msg_ts);
 #endif
 						eval = E2BIG;
 						goto msgrcvout;
 					}
+#if CONFIG_MACF
+					eval = mac_sysvmsq_check_msgrcv(
+					    kauth_cred_get(), msghdr);
+					if (eval) 
+						goto msgrcvout;
+#endif
 					*prev = msghdr->msg_next;
-					if (msghdr == msqptr->msg_last) {
+					if (msghdr == msqptr->u.msg_last) {
 						if (previous == NULL) {
 							if (prev !=
-							    &msqptr->msg_first)
+							    &msqptr->u.msg_first)
 								panic("msg_first/last messed up #2");
-							msqptr->msg_first =
+							msqptr->u.msg_first =
 							    NULL;
-							msqptr->msg_last =
+							msqptr->u.msg_last =
 							    NULL;
 						} else {
 							if (prev ==
-							    &msqptr->msg_first)
+							    &msqptr->u.msg_first)
 								panic("msg_first/last messed up #3");
-							msqptr->msg_last =
+							msqptr->u.msg_last =
 							    previous;
 						}
 					}
@@ -1065,7 +1300,7 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 
 		if ((msgflg & IPC_NOWAIT) != 0) {
 #ifdef MSG_DEBUG_OK
-			printf("no appropriate message found (msgtyp=%d)\n",
+			printf("no appropriate message found (msgtyp=%ld)\n",
 			    msgtyp);
 #endif
 			/* The SVID says to return ENOMSG. */
@@ -1103,8 +1338,8 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 		 * Make sure that the msq queue still exists
 		 */
 
-		if (msqptr->msg_qbytes == 0 ||
-		    msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
+		if (msqptr->u.msg_qbytes == 0 ||
+		    msqptr->u.msg_perm._seq != IPCID_TO_SEQ(uap->msqid)) {
 #ifdef MSG_DEBUG_OK
 			printf("msqid deleted\n");
 #endif
@@ -1125,10 +1360,10 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 	 * First, do the bookkeeping (before we risk being interrupted).
 	 */
 
-	msqptr->msg_cbytes -= msghdr->msg_ts;
-	msqptr->msg_qnum--;
-	msqptr->msg_lrpid = p->p_pid;
-	msqptr->msg_rtime = sysv_msgtime();
+	msqptr->u.msg_cbytes -= msghdr->msg_ts;
+	msqptr->u.msg_qnum--;
+	msqptr->u.msg_lrpid = p->p_pid;
+	msqptr->u.msg_rtime = sysv_msgtime();
 
 	/*
 	 * Make msgsz the actual amount that we'll be returning.
@@ -1137,7 +1372,7 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 	 */
 
 #ifdef MSG_DEBUG_OK
-	printf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
+	printf("found a message, msgsz=%ld, msg_ts=%d\n", msgsz,
 	    msghdr->msg_ts);
 #endif
 	if (msgsz > msghdr->msg_ts)
@@ -1158,11 +1393,11 @@ msgrcv(struct proc *p, struct msgrcv_args *uap, user_ssize_t *retval)
 		SYSV_MSG_SUBSYS_LOCK();
 		user_msgp = user_msgp + sizeof(msgtype);	/* ptr math */
 	} else {
-		msg_type_long = msghdr->msg_type;
+		msg_type32 = msghdr->msg_type;
 		SYSV_MSG_SUBSYS_UNLOCK();
-		eval = copyout(&msg_type_long, user_msgp, sizeof(long));
+		eval = copyout(&msg_type32, user_msgp, sizeof(msg_type32));
 		SYSV_MSG_SUBSYS_LOCK();
-		user_msgp = user_msgp + sizeof(long);		/* ptr math */
+		user_msgp = user_msgp + sizeof(msg_type32);		/* ptr math */
 	}
 
 	if (eval != 0) {
@@ -1230,18 +1465,22 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 	int error;
 	int cursor;
 	union {
-		struct IPCS_command u32;
+		struct user32_IPCS_command u32;
 		struct user_IPCS_command u64;
 	} ipcs;
-	struct msqid_ds msqid_ds32;	/* post conversion, 32 bit version */
+	struct user32_msqid_ds msqid_ds32;	/* post conversion, 32 bit version */
+	struct user64_msqid_ds msqid_ds64;	/* post conversion, 64 bit version */
 	void *msqid_dsp;
-	size_t ipcs_sz = sizeof(struct user_IPCS_command);
-	size_t msqid_ds_sz = sizeof(struct user_msqid_ds);
+	size_t ipcs_sz;
+	size_t msqid_ds_sz;
 	struct proc *p = current_proc();
 
-	if (!IS_64BIT_PROCESS(p)) {
-		ipcs_sz = sizeof(struct IPCS_command);
-		msqid_ds_sz = sizeof(struct msqid_ds);
+	if (IS_64BIT_PROCESS(p)) {
+		ipcs_sz = sizeof(struct user_IPCS_command);
+		msqid_ds_sz = sizeof(struct user64_msqid_ds);
+	} else {
+		ipcs_sz = sizeof(struct user32_IPCS_command);
+		msqid_ds_sz = sizeof(struct user32_msqid_ds);
 	}
 
 	/* Copy in the command structure */
@@ -1276,7 +1515,10 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 
 	case IPCS_MSG_ITER:	/* Iterate over existing segments */
 		/* Not done up top so we can set limits via sysctl (later) */
-		msginit( 0);
+		if (!msginit(0)) {
+			error =  ENOMEM;
+			break;
+		}
 
 		cursor = ipcs.u64.ipcs_cursor;
 		if (cursor < 0 || cursor >= msginfo.msgmni) {
@@ -1284,11 +1526,11 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 			break;
 		}
 		if (ipcs.u64.ipcs_datalen != (int)msqid_ds_sz) {
-			error = ENOMEM;
+			error = EINVAL;
 			break;
 		}
 		for( ; cursor < msginfo.msgmni; cursor++) {
-			if (msqids[cursor].msg_qbytes != 0)	/* allocated */
+			if (msqids[cursor].u.msg_qbytes != 0)	/* allocated */
 				break;
 			continue;
 		}
@@ -1303,10 +1545,14 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 		 * If necessary, convert the 64 bit kernel segment
 		 * descriptor to a 32 bit user one.
 		 */
-		if (!IS_64BIT_PROCESS(p)) {
-			msqid_ds_64to32(msqid_dsp, &msqid_ds32);
+		if (IS_64BIT_PROCESS(p)) {
+			msqid_ds_kerneltouser64(msqid_dsp, &msqid_ds64);
+			msqid_dsp = &msqid_ds64;
+		} else {
+			msqid_ds_kerneltouser32(msqid_dsp, &msqid_ds32);
 			msqid_dsp = &msqid_ds32;
 		}
+
 		SYSV_MSG_SUBSYS_UNLOCK();
 		error = copyout(msqid_dsp, ipcs.u64.ipcs_data, ipcs.u64.ipcs_datalen);
 		if (!error) {
@@ -1314,7 +1560,7 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 			ipcs.u64.ipcs_cursor = cursor + 1;
 
 			if (!IS_64BIT_PROCESS(p))	/* convert in place */
-				ipcs.u32.ipcs_data = CAST_DOWN(void *,ipcs.u64.ipcs_data);
+				ipcs.u32.ipcs_data = CAST_DOWN_EXPLICIT(user32_addr_t,ipcs.u64.ipcs_data);
 			error = SYSCTL_OUT(req, &ipcs, ipcs_sz);
 		}
 		SYSV_MSG_SUBSYS_LOCK();
@@ -1330,7 +1576,9 @@ IPCS_msg_sysctl(__unused struct sysctl_oid *oidp, __unused void *arg1,
 }
 
 SYSCTL_DECL(_kern_sysv_ipcs);
-SYSCTL_PROC(_kern_sysv_ipcs, OID_AUTO, msg, CTLFLAG_RW|CTLFLAG_ANYBODY,
+SYSCTL_PROC(_kern_sysv_ipcs, OID_AUTO, msg, CTLFLAG_RW | CTLFLAG_ANYBODY | CTLFLAG_LOCKED,
 	0, 0, IPCS_msg_sysctl,
 	"S,IPCS_msg_command",
 	"ipcs msg command interface");
+
+#endif /* SYSV_MSG */